• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.783-790
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• 2007

The immobilization of proteins and their molecular interactions on various polymer-modified glass substrates [i.e. 3-aminopropyltriethoxysilane (APTS), 3-glycidoxypropyltrimethoxysilane (GPTS), poly (ethylene glycol) diacrylate (PEG-DA), chitosan (CHI), glutaraldehyde (GA), 3-(trichlorosilyl)propyl methacrylate (TPM), 3'-mercaptopropyltrimethoxysilane (MPTMS), glycidyl methacrylate (GMA) and poly-l-lysine (PL).] for potential applications in a nanoarray protein chip at the single-molecule level was evaluated using prismtype dual-color total internal reflection fluorescence microscopy (dual-color TIRFM). A dual-color TIRF microscope, which contained two individual laser beams and a single high-sensitivity camera, was used for the rapid and simultaneous dual-color detection of the interactions and colocalization of different proteins labeled with different fluorescent dyes such as Alexa Fluor® 488, Qdot® 525 and Alexa Fluor® 633. Most of the polymer-modified glass substrates showed good stability and a relative high signal-to-noise (S/N) ratio over a 40-day period after making the substrates. The GPTS/CHI/GA-modified glass substrate showed a 13.5-56.3% higher relative S/N ratio than the other substrates. 1% Top-Block in 10 mM phosphate buffered saline (pH 7.4) showed a 99.2% increase in the blocking effect of non-specific adsorption. These results show that dual-color TIRFM is a powerful methodology for detecting proteins at the single-molecule level with potential applications in nanoarray chips or nano-biosensors.

• Structural Engineering and Mechanics
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• 제56권5호
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• pp.813-833
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• 2015

Spherical reticulated shells are widely applied in structural engineering due to their good bearing capability and attractive appearance. Parametric modeling of spherical reticulated shells is the basis of internal analysis and optimization design. In the present study, generation methods of nodes and the corresponding connection methods of rod elements are proposed. Modeling programs are compiled by adopting the ANSYS Parametric Design Language (APDL). A shape optimization method based on the two-stage algorithm is presented, and the corresponding optimization program is compiled in FORTRAN environment. Shape optimization is carried out based on the objective function of the minimum total steel consumption and the restriction condition of strength, stiffness, slenderness ratio, stability. The shape optimization of four typical Schwedler spherical reticulated shells is calculated with the span of 30 m~80 m and rise to span ratio of 1/7~1/2. Compared with the shape optimization results, the variation rules of total steel consumption along with the span and rise to span ratio are discussed. The results show that: (1) The left and right rod-Schwedler spherical reticulated shell is the most optimized and should be preferentially adopted in structural engineering. (2) The left diagonal rod-Schwedler spherical reticulated shell is second only to left and right rod regarding the mechanical behavior and optimized results. It can be applied to medium and small-span structures. (3) Double slash rod-Schwedler spherical reticulated shell is advantageous in mechanical behavior but with the largest total weight. Thus, this type can be used in large-span structures as far as possible. (4) The mechanical performance of no latitudinal rod-Schwedler spherical reticulated shell is the worst and with the second largest weight. Thus, this spherical reticulated shell should not be adopted generally in engineering.

• 농업과학연구
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• 제19권1호
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• pp.103-114
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• 1992

항산화성 생약을 선발하기 위하여 180종의 생약을 10배량의 methanol 로 추출한 액 $50{\mu}l$와 0.1M-linoleic acid ethanol 용액 $100{\mu}l$를 넣은 시험관을 $50^{\circ}C$에서 20시간 두었다가 POV를 측정하는 방법으로 항산화성을 측정하였을 때 45% 이상의 생약 추출물이 항산화성을 나타내었고 그 중 44종 의 생약추출물의 항산화성은 비교적 강력하였다. 단기 항산화시험에 의해서 항산화성이 비교적 강한 것으로 나타난 44종의 생약을 10배량의 methanol로 추출한액 3ml, 0.1M-methyl linoleate ethanol 용액 10ml 및 0.1M-sodium phosphate buffer(pH 7.0) 37ml를 혼합하여 $40^{\circ}C$에서 35일간 저장하면서 POV의 변화를 측정하였던 바 삼백초, 세신, 진범, 음양곽, 백굴체, 소회향, 고삼, 정향, 황금, 감초 및 파고지 동 11종의 생약추출물의 항산화성이 특히 강하였다. Methan이 추출액의 항산화성이 특히 강하였던 11종의 생약을 ethyl acetate 및 petroleum ether로 추출하여 항산화성을 비교하였을 때 음양곽, 소회향, 정향 및 파고지는 추출용매의 종류에 관계없이 강한 항산화성을 나타내었으나 황금 및 감초 등은 methanol 추출액에서만 강한 항산화능이 나타났다.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.65-70
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• 2006

An amperometric glucose biosensor has been developed based on the use of the nanoporous composite film of sol-gel-derived zirconia and perfluorosulfonated ionomer, Nafion, for the encapsulation of glucose oxidase (GOx) on a platinized glassy carbon electrode. Zirconium isopropoxide (ZrOPr) was used as a sol-gel precursor for the preparation of zirconia/Nafion composite film and the performance of the resulting glucose biosensor was tuned by controlling the water content in the acid-catalyzed hydrolysis of sol-gel stock solution. The presence of Nafion polymer in the sol-gel-derived zirconia in the biosensor resulted in faster response time and higher sensitivity compared to those obtained at the pure zirconia- and pure Nafion-based biosensors. Because of the nanoporous nature of the composite film, the glucose biosensor based on the zirconia/Nafion composite film can reach 95% of steady-state current less than 5 s. In addition, the biosensor responds to glucose linearly in the range of 0.03-15.08 mM with a sensitivity of 3.40 $\mu$A/mM and the detection limit of 0.037 mM (S/N = 3). Moreover, the biosensor exhibited good sensor-to-sensor reproducibility (~5%) and long-term stability (90% of its original activity retained after 4 weeks) when stored in 50 mM phosphate buffer at pH 7 at 4 ${^{\circ}C}$.

• 한국식품과학회지
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• 제11권3호
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• pp.200-205
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• 1979

인산 염(monosodium phosphate, disodium phosphate, trisodium phosphate, ${\alpha}-polygel$ 및 sodium tripolyphosphate)이 Lactobacillus bulgaricus 단독 배양 및 Lactobacillus bulgari쳐s와 Streptococcus thermophilus의 혼합 배양(혼합비 1:1)에 미치는 영향을 검토하였다. 인산 염은 유산균의 생장을 촉진하였으며 특히 단독 배양의 경우 MSP와 STPP가, 혼합 배양의 경우 MSP와 DSP가 가장 효과적이었다. 산도도 유산균의 증식과 동일한 결과를 보였다. 배양액을 실온에서 저장하는 동안 생균 수의 감소는 인산 염 처리구가 대조구에 비하여 완만하였으며 단독 배양시 특히 DSP와 TSP가 효과적이었고 혼합 배양의 경우 TSP와 ${\alpha}-PG$가 가장 효과적이었다. 혼합 균주를 사용하여 제조된 발효유의 저장 중 안정성은 인산염 처리구가 대조구보다 좋았으며 특히 MSP가 가장 효과적이었다.

• 한국지반공학회논문집
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• 제19권2호
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• pp.159-170
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• 2003

본 연구에서는 재료분야에서 최근의 기술동향인 고강도.고침투성.고내구성 및 환경에 대한 안정성이 높은 주입재료의 배합설계를 실시하여 주입목적, 지반조건에 따른 주입효과와 환경적 영향성을 분석.검토함으로써 현장적용시 주입설계의 기초자료로 제안하고자 한다. 주입재의 물리, 역학.화학적 특성 및 입자형상을 파악하고 작업성과 침투범위 조정에 필수적인 겔타임을 조정하였다. 또한 실내모형시험을 통하여 고결성, 침투성 및 내구성 평가를 수행하였다. 환경적 영향평가를 위해 본 연구에서 사용된 재료는 현장에서 일반적으로 사용되는 보통포틀랜드시멘트, 고로슬래그시멘트와 초미립자시멘트를 사용하였다. 시멘트계 그라우트재에서의 6가 크롬의 용출특성을 판단하기 위해 원재료의 6가크롬 함유량 시험과 pH변화에 따른 6가크롬의 용출변화량 시험 그리고 그라우트가 적용되는 주변환경에 따른 특성파악을 위해 호모겔을 제작하여 양생수를 각각 초순수, 침출수로 하여, 양생수에 따른 그라우트 호모겔의 일축압축강도 및 6가크롬 용출량의 변화를 시험하였다.

• 한국패션뷰티학회지
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• 제5권4호
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• pp.130-138
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• 2007

The aim of this study was to assess the cosmeceutical activies of four kinds of Korea herb medicine extracts using in cosmetics and related industries. The cosmeceutical activities of extracts were investigated by tyrosinase inhibition, astringent, anti-bacterial and MTT assay for cell viability. In the whitening effect, PA that the highest tyrosinase inhibition activity showed 56% at 10 ppm in ethanol extract. Also water and ethanol extract of RE showed 54%, 68% at 1,000 ppm, respectively, but LE and CA showed lower effect. Astringent effect of water and ethanol extract of PA appeared over 60% at 1,000ppm concentration but other extracts showed no astringent effect. In the anti-bacterial test, water and ethanol extract of PA showed no anti-bacterial effect against all microorganisms. But water and ethanol extract of RE showed anti-bacterial effect on Staphylococcus aureus, ethanol extract of showed on Staphylococcus aureus and Propionibacterium acnes, ethanol extract of CA showed on Candida albicans. The resUlt of stability test showed that the emulsion of containing PA were very stable at various temperature and sun-light test. Viscosity and pH of emulsion did not change. From the results of human patch test to assess the safety of cosmetics containing PA there was no negative reaction on skin was found.

• Wind and Structures
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• 제10권5호
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• pp.463-479
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• 2007

A series of wind tunnel sectional model dynamic tests of a twin-deck bridge were conducted at the CLP Power Wind/Wave Tunnel Facility (WWTF) of The Hong Kong University of Science and Technology (HKUST) to investigate the effects of gap-width on the self-excited vibrations and the dynamic and aerodynamic characteristics of the bridge. Five 2.9 m long models with different gap-widths were fabricated and suspended in the wind tunnel to simulate a two-degrees-of-freedom (2DOF) bridge dynamic system, free to vibrate in both vertical and torsional directions. The mass, vertical frequency, and the torsional-to-vertical frequency ratio of the 2DOF systems were fixed to emphasize the effects of gap-width. A free-vibration test methodology was employed and the Eigensystem Realization Algorithm (ERA) was utilized to extract the eight flutter derivatives and the modal parameters from the coupled free-decay responses. The results of the zero gap-width configuration were in reasonable agreement with the theoretical values for an ideal thin flat plate in smooth flow and the published results of models with similar cross-sections, thus validating the experimental and analytical techniques utilized in this study. The methodology was further verified by the comparison between the measured and predicted free-decay responses. A comparison of results for different gap-widths revealed that variations of the gap-width mainly affect the torsional damping property, and that the configurations with greater gap-widths show a higher torsional damping ratio and hence stronger aerodynamic stability of the bridge.

• Journal of Pharmaceutical Investigation
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• 제21권2호
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• pp.67-71
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• 1991

A simple and sensitive method was developed for the quantification of free and conjugated bile acids in bezoar without prior hydrolysis. $3{\alpha}-Hydroxy$ bile acids are first oxidized to 3-keto bile acids in the reaction catalyzed by $3{\alpha}-hydroxysteroid$ $dehydrogenase(3{\alpha}-HSD)$. During this oxidative reaction, an equimolar quantity of nicotinamide adenine dinucleotide(NAD) is reduced to NADH and subsequently oxidized to NAD with concomitant reduction of nitrotetrazolium blue(NTB) to diformazan by the catalytic action of diaphorase. The diformazan has an absorbance maximum at 540 nm. The intensity of the color produced is directly proportional to bile acids concentration in the bezoar extracts. The optimum conditions for the enzymatic reaction such as effects of reaction time, reaction temperature and pH, and stability were investigated. Calibration plots for the sodium chelate observed to be linear and intra-, inter-assay analytical recovery of bile acids averaged $97.65{\pm}3.4%(S.D.)$. Therefore, it is considered that the quality control of total bile acids from bezoar or bezoar-containing liquid preparation using this simple and sensitive assay system will be acceptable. Also current bezoars and bezoar-containing liauid preparations were examined their total bile acids from this method.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1067-1076
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• 2016

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30℃ and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0℃ and good stability at temperatures below 35℃. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30℃. Its activity was slightly affected by some metal ions such as K⁺, Ca²⁺, and Na⁺. The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.